Don't take this review as gospel for this device, because I haven't really put this device through it's paces yet to find out how it copes under heavy strain, but going from the look and apparant quality of the item, I'm very impressed.
And as for the "quiet" aspect - when I connected this up and powered it on, I could barely hear the thing. And that was without it even being placed inside a computer case. I had the thing powered up and sitting out right in front of me, and I actually had to put my hand over the fan to see if I could feel air coming from it. It was only when I could I was convinced the thing was even on because I could barely hear a thing.
If computer noise is one of your pet-hates, you definitely want to consider this as an option to your PSU needs.